<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
    
  </style>
</head>
<body>
  
</body>
<script>

  console.log(0.1 + 0.1);
  console.log(0.1 + 0.2);
  console.log(0.1 + 0.3);

  var a = 0.1 + 0.2;
  console.log( Number(a.toFixed(5)) );

  
</script>
</html>